Introduced in 1973 as the replacement for the hugely successful 1100/1300 range the Austin Allegro is possibly unique in the car world - because I can think of no other car which was worse than the car it replaced in almost every respect.
To be fair, the "All aggro" had a very hard act to follow in the classic Issigonis designed ADO16 and it wasn't the fault of the car that the launch was more about what the car wasn't than what it was.
Despite its appearance, it wasn't a hatchback, it wasn't very good looking (in fact it was downright ugly) and it wasn't very well put together. Other than that, the only thing that grabbed attention was the square "Quartic" steering wheel - an innovation so successful that it was dropped soon after launch. Perhaps the most remarkable thing about the Allegro is that it survived in production for ten years and more than half a million of the things found owners.
The nickname "All aggro" was also largely deserved with problems with the "Hydragas" suspension which tended to either make the occupants feel sea sick or leave the car spreadeagled on roads like Bambi on ice.
I only drove an Allegro once - and that was more than enough for me. It wasn't a driver's car. However, it was a very pleasant car to be driven in (as long as you could handle the suspension) because it was very spacious inside with plenty of rear legroom and headroom.
There must have been something about the Allegro, though, because there still seem to be a fair few of them on our roads in regular use and I know two people who have had nothing but Allegros for the last 20 years. I've no idea what it is about the car, but they appear to survive better than just about anything else from that era. There could be any number of reasons for that, but I suspect that it is just the great British tradition of supporting the underdog.